Integer types (byte, short, int, long)

Integer types

Java provides four integer types to represent whole numbers. Choose the smallest type that fits your range to save memory.

Type	Size	Range	Use case
byte	1 byte	-128 to 127	small counters, file I/O, network data
short	2 bytes	-32,768 to 32,767	rarely used, mostly for compatibility
int	4 bytes	-2³¹ to 2³¹‑1	default integer type, most common
long	8 bytes	-2⁶³ to 2⁶³‑1	large numbers (e.g., timestamps, large counts)

Literals:

• Decimal: int i = 100;
• Octal (prefix 0): int octal = 012; // decimal 10
• Hexadecimal (prefix 0x): int hex = 0x1A; // decimal 26
• Binary (prefix 0b): int bin = 0b1010; // decimal 10
• Underscores: int million = 1_000_000;

Long literals must end with L or l:

long big = 2_147_483_648L;   // beyond int range

Operations:

int a = 10, b = 3;
int sum = a + b;      // 13
int product = a * b;  // 30
int division = a / b; // 3 (integer division truncates)
int remainder = a % b; // 1

Be careful with overflow: if the result exceeds the range, it wraps around silently.

int max = Integer.MAX_VALUE; // 2_147_483_647
int overflow = max + 1;      // becomes -2_147_483_648